*{
    margin: 0;
    padding: 0;
}
.box{
    background-color:#eee;
    text-align: center;
}
.countent{
    width: 500px;
    height: 500px;
    margin:0 auto;
}
input{
    width: 300px;
    height: 30px;
    margin-top:20px; 
}
.submit{
    margin-top: 20px;
    width: 150px;
    background: yellowgreen;
    color: #fff;
}